Air data probe corrosion protection

ABSTRACT

A method can include vapor depositing a corrosion resistant coating to internal and external surfaces of a metallic air data probe. For example, vapor depositing can include using atomic layer deposition (ALD). The method can include placing the metallic air data probe in a vacuum chamber and evacuating the vacuum chamber before using vapor deposition. The corrosion resistant coating can be or include a ceramic coating. In certain embodiments, vapor depositing can include applying a first precursor, then applying a second precursor to the first precursor to form the ceramic coating.

BACKGROUND 1. Field

The present disclosure relates to air data probes, more specifically tocorrosion protection for air data probes.

2. Description of Related Art

Air data probes can experience external and internal corrosion, e.g., onaircraft that operate in coastal routes and/or due to sulfur fromaircraft exhaust. Certain air data probes can be made of nickel and/orother corrosion resistant material that experiences sporadic temperaturefluxes at greater than 1000 degrees F. Contaminants, e.g., sulfur in theatmosphere, accelerate corrosion on nickel leading to sulfidation thatpenetrates the nickel sheath which can affect heater function. Ceramiccoatings have been attempted, but bulk deposition does not provide lowporous films as well as internal corrosion protection. In addition, suchmaterials coated on the exterior surface must be resistant to erosiveconditions, such as rain, wind, or sand.

Such conventional methods and systems have generally been consideredsatisfactory for their intended purpose. However, there is still a needin the art for improved air date probe corrosion protection. The presentdisclosure provides a solution for this need.

SUMMARY

A method can include vapor depositing a corrosion resistant coating tointernal and external surfaces of a metallic air data probe. Forexample, vapor depositing can include using chemical vapor deposition(CVD) or atomic layer deposition (ALD). The method can include placingthe metallic air data probe in a vacuum chamber and evacuating thevacuum chamber before using vapor deposition. The corrosion resistantcoating can be or include a ceramic coating. In certain embodiments,vapor depositing can include applying a first precursor, then applying asecond precursor to the first precursor to form the ceramic coating.

In certain embodiments, the ceramic coating can be an oxide or anitride. The final film can be either amorphous or crystalline,depending on the material. The first precursor gas can be or come fromany volatile compound of: Al, Si, Ti, Zr, Hf, Ta, Nb, Sc, Y, Mg, La, Ce,Pr, W, Ni, Cu, Fe, Cr, Co, Mn, B, Zn, Li, V, Mo, and Sr. The secondprecursor can be an oxide former including water, ozone, or O₂ plasma,or any other suitable compound. For example, the ceramic coating can besilicon dioxide (SiO₂), the first precursor can be a reactive, volatilesilicon effluent, e.g. dichlorosilane (SiH₂Cl₂), and the secondprecursor can be an oxide former, e.g. ozone (O₃).

For example, in certain embodiments, the ceramic coating can be aluminumoxide (Al₂O₃), the first precursor can be a reactive, volatile aluminumeffluent, e.g. triethyl aluminum, and the second precursor can be anoxide former, e.g. water vapor. Applying the second precursor caninclude applying heat simultaneously (e.g., about 100 degrees C. foraluminum oxide). In certain embodiments, the ceramic coating can beTantalum Pentoxide (Ta₂O₅) or Zirconium Oxide (ZrO₂). Any suitableprecursors for any suitable oxides are contemplated herein.

The ceramic coating can be one of titanium nitride (TiN), titaniumaluminum nitride (TiAlN), zirconium nitride or tantalum nitride (TaN)(e.g., to provide erosion resistance to the pinhole free coating sinceoxides may not have sufficient erosion resistance). Certain embodimentscan utilize a cationic species (Ti, TiAl, Ta, Zr) with nitride formersof ammonia, plasma assisted ammonia, plasma assisted nitrogen (N₂), orhydrazine. In certain embodiments, the first precursor can include areactive, volatile material, e.g. titanium chloride, and the secondprecursor can include a nitride former, such as ammonia. Applying thefirst precursor can include applying heat simultaneously (e.g., about500 degrees C.).

Any suitable precursors for any suitable nitrides are contemplatedherein. Any suitable combination(s) of any oxides and/or nitrides, suchas nanolaminate stacks, are contemplated herein.

Vapor deposition can include applying a noble metallic layer to the airdata probe before applying the first precursor. Applying the firstprecursor can include applying the first precursor to the metalliclayer.

The metallic layer can include at least one of platinum, Pd, or Ru,e.g., having a thickness between about 5 nm to about 20 nm. Any othersuitable metal and/or thickness is contemplated herein. In certainembodiments, the metal can include gold or any other suitable metal. Themetal can be applied via vapor deposition if possible, and/or viaelectroplating or any other suitable method before vapor deposition ofother layers.

The corrosion resistant coating can be about 10 nm to about 3 micronthick. Any other suitable overall thickness is contemplated herein.

The metallic air data probe can be or include nickel (e.g., a nickelalloy). Any other suitable material for the air data probe iscontemplated herein.

In accordance with at least one aspect of this disclosure, an air dataprobe can include a metallic body defining internal and externalsurfaces. The air data probe can include a substantially uniformvapor-deposited corrosion resistant coating disposed on all internal andexternal surfaces of the metallic body.

These and other features of the systems and methods of the subjectdisclosure will become more readily apparent to those skilled in the artfrom the following detailed description taken in conjunction with thedrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

So that those skilled in the art to which the subject disclosureappertains will readily understand how to make and use the devices andmethods of the subject disclosure without undue experimentation,embodiments thereof will be described in detail herein below withreference to certain figures, wherein:

FIG. 1 is a cross-sectional view of an embodiment of an air data probein accordance with this disclosure;

FIGS. 2A-2D show a partial, cross-sectional view of the embodiment ofFIG. 1 being coated in accordance with at least one embodiment of amethod in accordance with this disclosure; and

FIG. 3 shows a partial, cross-sectional view of the embodiment of FIG. 1being coated in accordance with at least one embodiment of a method inaccordance with this disclosure, shown having a metallic layer disposedon the body.

DETAILED DESCRIPTION

Reference will now be made to the drawings wherein like referencenumerals identify similar structural features or aspects of the subjectdisclosure. For purposes of explanation and illustration, and notlimitation, an illustrative view of an embodiment of an air data probein accordance with the disclosure is shown in FIG. 1 and is designatedgenerally by reference character 100. Other embodiments and/or aspectsof certain embodiments of this disclosure are shown in FIGS. 2A-3 . Thesystems and methods described herein can be used to provide corrosionresistance to one or more air data probes, for example.

In accordance with at least one aspect of this disclosure, referring toFIG. 1 , an air data probe 100 can include a metallic body 101 (e.g., anickel alloy or any other suitable material) defining internal andexternal surfaces 103, 105. The air data probe 100 can include asubstantially uniform vapor-deposited corrosion resistant coating (e.g.,as described below and as shown in FIG. 2D) disposed on all internal andexternal surfaces of the metallic body 101.

A method can include vapor depositing a corrosion resistant coating(e.g., as shown in FIGS. 2A-2D) to internal and external surfaces 103,105 of a metallic air data probe 100. For example, vapor depositing caninclude using chemical vapor deposition (CVD) or atomic layer deposition(ALD). Any other suitable type of deposition is contemplated herein.

Referring to FIGS. 2A-2D, a partial cross-sectional view of a portion(e.g., a static pressure port) is shown. In certain embodiments, asshown in FIG. 2A, the method can include placing the metallic air dataprobe 100 in a vacuum chamber (not shown) and evacuating the vacuumchamber before using vapor deposition.

In certain embodiments, vapor depositing can include applying a firstprecursor 107, as shown in FIG. 2B. Vapor depositing can includeapplying a second precursor 109 to the first precursor 107, e.g., asshown in FIG. 2C, to form at least a first layer of the corrosionresistant coating 113 (e.g., ceramic), e.g., as shown in FIG. 2D. Asappreciated by those having ordinary skill in the art in view of thisdisclosure, the second precursor 109 can be configured to react with thefirst precursor 107 to form the coating 113.

Applying precursors can be repeated to form a coating 113 of any desiredthickness having any suitable number layers with the same and/ordifferent material compositions. Any additional number of precursors toform at least a layer of coating 113 is contemplated herein.

In certain embodiments, the corrosion resistant coating 113, can be orinclude a ceramic coating. In certain embodiments, the ceramic coatingcan be an oxide or a nitride. The final film can be either amorphous orcrystalline, depending on the material. The first precursor gas can beor come from any volatile compound of: Al, Si, Ti, Zr, Hf, Ta, Nb, Sc,Y, Mg, La, Ce, Pr, W, Ni, Cu, Fe, Cr, Co, Mn, B, Zn, Li, V, Mo, and Sr.The second precursor can be an oxide former including water, ozone, orO₂ plasma, or any other suitable compound. For example, the ceramiccoating can be silicon dioxide (SiO₂), the first precursor can be areactive, volatile silicon effluent, e.g. dichlorosilane (SiH₂Cl₂), andthe second precursor can be an oxide former, e.g. ozone (O₃).

In certain embodiments, the ceramic coating 113 can be Aluminum Oxide(Al₂O₃), the first precursor 107 can be triethyl aluminum, and thesecond precursor 109 can be water vapor. For such an embodiment and/orfor any other suitable embodiments, applying the second precursor 109can include applying heat simultaneously (e.g., about 100 degrees C. forAluminum Oxide).

In certain embodiments, the ceramic coating 113 can be TantalumPentoxide (Ta₂O₅) or Zirconium Oxide (ZrO₂). Any suitable precursors forany suitable oxides are contemplated herein.

Any suitable material for the ceramic coating 113 is contemplatedherein. For example, the ceramic coating can be or include one or moreof Titanium Nitride (TiN), Titanium Aluminum Nitride (TiAlN), orTantalum Nitride (TaN). Certain embodiments can utilize a cationicspecies (Ti, TiAl, Ta, Zr) with nitride formers of ammonia, plasmaassisted ammonia, plasma assisted nitrogen (N₂), or hydrazine.

In certain embodiments, the first precursor 107 can include Titaniumchloride and the second precursor 109 can include zirconium nitride. Insuch embodiments and/or for any other suitable embodiments, applying thefirst and/or second precursor 107 can include applying heatsimultaneously (e.g., about 500 degrees C.). Any suitable precursors forany suitable nitrides are contemplated herein. Any suitablecombination(s) of any oxides and/or nitrides are contemplated herein.

Referring to FIG. 3 , in certain embodiments, vapor deposition caninclude applying a metallic layer 115 (e.g., a noble metallic layer) tothe air data probe 100 (e.g., directly to the body 101 as shown, or on acoating on the body 101) before applying the first precursor 107.Applying the first precursor 107 can include applying the firstprecursor to the metallic layer 115. The metallic layer 115 can beapplied using vapor deposition or in any other suitable manner (e.g.,electroplating).

The metallic layer 115 can include at least one of platinum, Pd, or Ru,e.g., having a thickness between about 5 nm to about 20 nm. Any othersuitable metal and/or thickness is contemplated herein. In certainembodiments, the metal can include gold or any other suitable metal. Themetal can be applied via vapor deposition if possible, and/or viaelectroplating or any other suitable method before vapor deposition ofother layers. For example, instead of vapor depositing gold, gold can beplated on (e.g., via electroplating or electroless plating), and thenadditional layers as disclosed herein can be applied with a vapordeposition process (e.g., ALD) to coat the gold and any bare areas notcovered by the metal plating process. The thickness of an electroplatedlayer (e.g., of gold) can be about 3000 nm, or any other suitablethickness.

The corrosion resistant coating 113 can be about 10 nm to about 5 micronthick (e.g., 2 microns). Any other suitable overall thickness iscontemplated herein.

The metallic air data probe 100 can be or include nickel or a nickelalloy (e.g., Nickel 201, Inconel 625, 718, X-750). Any other suitablematerial for the air data probe 100 is contemplated herein.

Embodiments, e.g., utilizing ALD, allow non-line-of-site deposition ofmaterials. In embodiments, a first precursor is deposited and then asecond precursor is deposited thereon that reacts with the firstprecursor to form at least a first layer of a coating 113. Embodimentscan be used to substantially uniformly coat complicated internalgeometry with very small internal passages of certain air data probeswhere it was not previously possible. For example, embodiments canprovide a coating that is uniform to within about 5 nm to about 10 nmthroughout an air data probe.

In certain embodiments, vapor deposited ceramic coatings, e.g., atomiclayer deposition, allows the ability to coat both the internal andexternal surfaces using non-line-of-site methods. Due to the depositionmechanism, the coatings are pin-hole free, resulting in a more uniformcoating. In addition, the coatings are thin and highly controlled,allowing minimal disturbance to the aerodynamics and heater performanceof certain air data probes. Certain embodiments can improve rain erosionresistance of the coating. Embodiments can provide a coating needed forinternal/external surfaces while maintaining erosion resistance.Embodiments can include at least one sulfidation-resistant layer usingmaterials such as but not limited to Platinum (Pt).

Embodiments lower surface roughness and scaling of metal (e.g., nickel)due to oxidation. Embodiments increase heater lifetime due to reducedpitting of the metal sheath. Embodiments can also provide a hightemperature resistant coating and/or can be batch coated to lower costof applying the coating.

Those having ordinary skill in the art understand that any numericalvalues disclosed herein can be exact values or can be values within arange. Further, any terms of approximation (e.g., “about”,“approximately”, “around”, “substantially”) used in this disclosure canmean the stated value within a range. For example, in certainembodiments, the range can be within (plus or minus) 20%, or within 10%,or within 5%, or within 2%, or within any other suitable percentage ornumber as appreciated by those having ordinary skill in the art (e.g.,for known tolerance limits or error ranges).

Any suitable combination(s) of any disclosed embodiments and/or anysuitable portion(s) thereof are contemplated herein as appreciated bythose having ordinary skill in the art.

The embodiments of the present disclosure, as described above and shownin the drawings, provide for improvement in the art to which theypertain. While the subject disclosure includes reference to certainembodiments, those skilled in the art will readily appreciate thatchanges and/or modifications may be made thereto without departing fromthe spirit and scope of the subject disclosure.

What is claimed is:
 1. A method, comprising: metal plating a metalliclayer to at least a portion of a metallic air data probe before applyinga first precursor; vapor depositing a corrosion resistant coating tointernal and external surfaces of the metallic air data probe, whereinvapor depositing includes using chemical vapor deposition (CVD) oratomic layer deposition (ALD) on at least the portion of the metallicair data probe covered by the metallic layer and/or on at least aportion of the metallic air data probe not covered by the metalliclayer, wherein the corrosion resistant coating is a uniform thicknessacross the internal and external surfaces of the metallic air dataprobe, wherein the corrosion resistant coating is or includes a ceramiccoating, wherein vapor depositing includes applying the first precursor,then applying a second precursor to the first precursor to form theceramic coating, wherein applying the first precursor includes applyingthe first precursor to at least a portion of the metallic layer, whereinthe metallic layer includes at least one of platinum, Pd, Ru, or goldhaving a thickness between about 5 nm to about 20 nm.
 2. The method ofclaim 1, wherein the method includes placing the metallic air data probein a vacuum chamber and evacuating the vacuum chamber before using vapordeposition.
 3. The method of claim 1, wherein the ceramic coating is anoxide.
 4. The method of claim 3, wherein the ceramic coating is silicondioxide (SiO₂).
 5. The method of claim 4, wherein the first precursor isa reactive, volatile material and the second precursor is an oxideformer.
 6. The method of claim 3, wherein the ceramic coating isaluminum oxide (Al₂O₃).
 7. The method of claim 6, wherein the firstprecursor is triethyl aluminum and the second precursor is an oxideformer.
 8. The method of claim 7, wherein applying the second precursorincludes applying heat simultaneously.
 9. The method of claim 3, whereinthe ceramic coating is tantalum pentoxide (Ta₂O₅) or zirconium oxide.10. The method of claim 1, wherein the corrosion resistant coating isabout 10 nm to about 5 micron thick.
 11. The method of claim 1, whereinthe metallic air data probe is or includes nickel or nickel alloy. 12.The method of claim 1, wherein the ceramic coating is a nitride.
 13. Themethod of claim 12, wherein the ceramic coating is one of titaniumnitride (TiN), titanium aluminum nitride (TiAlN), zirconium nitride, ortantalum nitride (TaN).
 14. The method of claim 13, wherein the firstprecursor includes Titanium chloride and the second precursor includes anitride former.
 15. The method of claim 14, wherein applying the firstprecursor includes applying heat simultaneously.